In an unbiased p-n junction, how does increase in doping affect the width of Depletion Region? I read somewhere that width decreases as increase in carrier concentration leads to more recombination of majority carriers with oppositely charged ions of their depletion regions leading to a decrease in depletion width. But in the case of high doping , there will be a greater concentration gradient of charge carriers which should lead to a greater amount of diffusion current. A higher diffusion current implies more no. of ions on either side of the junction which in turn should increase the depletion width. How can we say then that depletion width decreases with increase in doping?